Serum and Tear Autoantibodies from NOD and NOR Mice as Potential Diagnostic Indicators of Local and Systemic Inflammation in Sjögren's Disease [MCF_SSK_546]. Serum and Tear Autoantibodies from NOD and NOR Mice as Potential Diagnostic Indicators of Local and Systemic Inflammation in Sjögren's Disease [MCF_SSK_546]

Sjögren's Disease (SjD) is an autoimmune disease characterized by lymphocytic infiltration of salivary and lacrimal glands (LG). The LG produces the protein-rich aqueous component of tears, and SjD-associated autoimmune dacryoadenitis (AD) may thus alter tear autoantibody composition. The presence of tertiary lymphoid structures (TLS) in LG from two murine models of SjD-associated AD, male non-obese diabetic (NOD) and male non-obese insulitis resistant (NOR) mice, were evaluated using immunofluorescence. IgG and IgA reactivity in serum and tears from these models were probed in three studies against a panel of 80-120 autoantigens using autoantibody microarrays relative to serum and tears from healthy male BALB/c mice. Sources of Ig in tears were investigated using scRNA-Seq of the LG (GSE132420). Data were analyzed by R package Limma and Seurat. Analysis of immunofluorescence in LG sections from both SjD models showed TLS. Only one autoantibody was significantly elevated in tears and serum in both SjD models across all studies. Three autoantibodies were significantly elevated in serum but not in tears in both SjD models across all studies. Conversely, six IgG and thirteen IgA autoantibodies (6 sharing the same autoantigen) were significantly elevated in tears but not serum in both SjD models. Igha and Ighg2b expressing cells were identified in the plasma cell cluster of NOD.H2b LG. NOD and NOR mice with SjD-associated AD have distinct autoantibody profiles in tears and serum. Tear IgA isotype autoantibodies showed a greater diversity than tear IgG autoantibodies. TLS observed in LG are a likely source of the tear autoantibodies. Overall design: Tear: male NOD (14 weeks, N=5), male NOR (16 weeks, N=4), male BALB/c (16 weeks, N=6). Serum: male NOD (14 weeks, N=5), male NOR (16 weeks, N=4), male BALB/c (16 weeks, N=6)

干燥综合征（Sjögren's Disease, SjD）是一类以唾液腺与泪腺（lacrimal glands, LG）发生淋巴细胞浸润为特征的自身免疫性疾病。泪腺可分泌富含蛋白质的泪液水相组分，因此伴干燥综合征的自身免疫性泪腺炎（dacryoadenitis, AD）可能改变泪液自身抗体的组成。本研究针对两种干燥综合征相关自身免疫性泪腺炎的小鼠模型——雄性非肥胖糖尿病（non-obese diabetic, NOD）小鼠与雄性非肥胖胰岛素抵抗（non-obese insulitis resistant, NOR）小鼠的泪腺，采用免疫荧光法对其中的三级淋巴结构（tertiary lymphoid structures, TLS）进行了评估。通过自身抗体微阵列，在三项研究中针对80~120种自身抗原组合，检测了上述模型小鼠血清与泪液中的IgG、IgA反应性，并以健康雄性BALB/c小鼠的血清与泪液作为对照。本研究采用泪腺单细胞RNA测序（scRNA-Seq，数据集编号GSE132420）探究了泪液中免疫球蛋白的来源。数据分析采用R包Limma与Seurat完成。对两种干燥综合征模型小鼠泪腺切片的免疫荧光分析结果显示存在三级淋巴结构。在所有研究中，仅有一种自身抗体在两种模型小鼠的泪液与血清中均显著升高。另有三种自身抗体在两种模型小鼠的血清中显著升高，但泪液中未检测到该变化。与之相反，有6种IgG自身抗体与13种IgA自身抗体（其中6种对应同一自身抗原）在两种模型小鼠的泪液中显著升高，而血清中未出现该变化。在NOD.H2b小鼠泪腺的浆细胞簇中，鉴定出了表达Igha与Ighg2b的细胞。伴干燥综合征相关自身免疫性泪腺炎的NOD与NOR小鼠，其泪液与血清中的自身抗体谱存在显著差异。泪液IgA类自身抗体的多样性高于泪液IgG类自身抗体。泪腺中观察到的三级淋巴结构极可能是泪液自身抗体的来源。整体实验设计：泪液样本：雄性NOD小鼠（14周龄，N=5）、雄性NOR小鼠（16周龄，N=4）、雄性健康BALB/c小鼠（16周龄，N=6）。血清样本：雄性NOD小鼠（14周龄，N=5）、雄性NOR小鼠（16周龄，N=4）、雄性健康BALB/c小鼠（16周龄，N=6）